CVE-2018-5732 : Vulnerability Insights and Analysis

A buffer overflow vulnerability in ISC DHCP versions 4.1.0 to 4.4.0 allows a malicious server to crash dhclient by sending a specially crafted response.

Understanding CVE-2018-5732

This CVE involves a buffer overflow issue in ISC DHCP that can be triggered by a malicious server, potentially leading to a crash in dhclient.

What is CVE-2018-5732?

The vulnerability arises from inadequate boundary checking in a buffer used for DHCP options processing, enabling a server to cause a buffer overflow in dhclient by sending a specific response.

The Impact of CVE-2018-5732

CVSS Base Score: 7.5 (High)
Attack Vector: Network
Availability Impact: High
No Confidentiality or Integrity Impact
No Privileges Required
Scope: Unchanged
The vulnerability could allow a remote attacker to crash the dhclient service.

Technical Details of CVE-2018-5732

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The buffer overflow occurs in dhclient due to insufficient boundary checks in DHCP options processing, triggered by a specially crafted server response.

Affected Systems and Versions

ISC DHCP versions 4.1.0 to 4.4.0 are impacted by this vulnerability.

Exploitation Mechanism

A malicious server can exploit the vulnerability by sending a crafted response containing specific options, leading to a buffer overflow in dhclient.

Mitigation and Prevention

Protecting systems from this vulnerability involves immediate actions and long-term security practices.

Immediate Steps to Take

Upgrade to the patched release closest to your current DHCP version.

Long-Term Security Practices

Implement operating system mitigation strategies like ASLR to make remote code execution more difficult.

Patching and Updates

Patch dhclient to prevent buffer overflow by upgrading to versions like DHCP 4.1-ESV-R15-P1, DHCP 4.3.6-P1, or DHCP 4.4.1.